A linear group sorting method and apparatus are provided. The linear ascending order of a half-bridge submodule and a full-bridge submodule in a Thevenin equivalent model of a semi-full hybrid MMC based on a trapezoidal integral method is conducted, and the linear ascending order of the half-bridge submodule and the full-bridge submodule is carried out once, and the ascending sequence of the capacitance voltage of the N sub-modules can be obtained only through3N-7 comparison. The method solve the technical problem that existing conventional sorting algorithm has high computational complexity and can not achieve the optimal simulation efficiency of a Thevenin equivalent model of a semi-full hybrid MMC based on a trapezoidal integral method without analyzing and combining the modeling process of a converter.